Klippel-Feil Syndrome (KFS) is a congenital defect characterized by the fusion of at least two cervical vertebrae. This article presents the case of a 12-year-old girl with KFS planned for scoliosis surgery. A short, rigid neck and limited mouth opening were predictors of difficult airway access. After failing multiple intubation attempts employing several devices, the case was postponed. Imaging tests showed lingual tonsil hypertrophy and a deviation of the tracheal axis, clarifying the causes of the failed intubation and suggesting new approaches for airway management. As far as we know, the association of KFS and lingual tonsil hypertrophy has not been reported before in the literature.